import java.util.Scanner;

import static java.lang.Math.sqrt;

public class PrimeNumber {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        boolean flag = false;
        int i = 2;
        for (; i < sqrt(n); i++) {
            if (n % i == 0) {
                flag = true;
                break;
            }
        }
        if (flag) {
            System.out.println(n + "不是素数");
        }else{
            System.out.println(n + "是素数");
        }

    }
}
